试题与答案

下列有关物质分离提纯的方法正确的是___________(填序号)。 ①由于碘在

题型:填空题

题目:

下列有关物质分离提纯的方法正确的是___________(填序号)。

①由于碘在酒精中的溶解度大,所以可用酒精将碘水中的碘萃取出来;

②水的沸点是100℃,酒精的沸点是78.5℃,所以可用直接加热蒸馏法使含水酒精变为无水酒精;

③由于胶粒的直径比离子大,所以淀粉溶液中混有的碘化钾可用渗析法分离;

④由于氯化钠的溶解度随温度变化改变较小,所以可用冷却法从热的含有少量硝酸钾的氯化钠浓溶液中分离得到纯净的氯化钠晶体;

⑤由于高级脂肪酸钠盐在水中的分散质微粒直径在1nm-100nm之间,所以可用食盐使高级脂肪酸纳从皂化反应后的混合物中析出;

⑥氯化氢气体极易溶于水,且饱和食盐水中的氯离子能促进反应C12+H2OHC1+HC1O向逆方向进行,所以用盛有饱和食盐水的洗气瓶,既可除去氯气中混有的少量氯化氢气体;

⑦由于粗铜中混有Zn、Fe等比Cu活泼的金属,电解时也会溶解,所以不可用电解法提炼高纯高的铜;

⑧除去FeC13溶液中有的少量FeC12:加入足量铁屑,充分反应后,过滤。

答案:

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题型:阅读理解

Below is adapted from a dictionary.

Water

▲Noun 1(a)[U] liquid without color, smell or taste that falls as ran, in lakes, rivets and seas, and is used for drinking, washing, etc: Water is changed into steam by heat and into ice by cold. ○drinking water ○ mineral water. (b)[U]this liquid as supplied to homes, factories, etc in pipes: The water was turned off for several hours a day during the drought. ○ hot and cold running water ○ [attrib] water shortages (c)[sing]mass of this liquid, esp a lake, river or sea: She fell into the water and drowned. ○ The flood water cowered the whole area. (d)[sing]surface of a lake, river, sea, etc: float on the water ○ We could see fishes under the water

2[U](exp in compounds)preparation containing water or sth similar to water: rose-water ○ soda-water

3 waters[pl](a)mass of water(in lake, river, etc)the (head-)waters of the Nile, ic the lake from which it flows(b)sea near a particular country: British waters ○ in home/ foreign waters 4[U]state or level of the tide: (at)high/low water

▲idioms he in /get into hot water(in formal) be in/get into trouble or disgrace: A person who

breaks a law can be in hot water with the police.

·cast one’s bread upon the waters(formal) do good make him drink you can give a person the

opportunity to do something but he may still refuse to do it.

·Still waters run deep a quiet or apparently calm person can have strong emotions, much

knowledge or wisdom.

·Blood is thicker than water Family is more important than anyone or anything else.

·Don’t throw the baby out with the bath water When deeds without expecting anything in

return:

·fish in troubled waters try to gain advantages for oneself from a disturbed state of affairs

·hold water(in formal)(of an argument, an excuse, etc)be capable of standing up to examination or

testing; be valid

·in smooth water(s) make even and easy progress: The business seems to be in smooth withers

there days.

·keep one’s head above water stay out of debt, difficulty etc: I’m managtag to keep my head

above water, though I am not earning much.

·pour oil on troubled waters (try to) calm a disagreement or violent dispute, etc

·water under the bridge event, mistake, etc that has already occurred and cannot be changed, so

there is no point in worrying about it.

verb [Tn] pour or sprinkle water on (sth): water a flowerbed, lawn, plant 2[Tn]give water to

(an animal) to drink 3[Tn] add water to (a drink )to dilute it: The owner of the pub was accused of

watering the beer.

Phrasal verb water sth down(a)make (a liquid)weaker by adding water(b)weaken the effect of

sth, eg by making the details less vivid: The criticisnts have been watered down so as not to offend

anybody.

▲Saying You can take a horse to water, but you can’t you are making a change, save what

matters to you and dispose of the rest

·It is no safe to wading in an unknown water it is dangerous for one to be involved in an

uncertain adventure.

·Too much water drowned the miller much gaining is good, but too much goes the opposite.

45.Fill in the blank in the sentence “If you’re caught cheating in the exam, you will___________.”

A.pour oil in troubled waters        B.be in hot water

C.cast your bread upon the waters      D.have to hold water

46.When we say it is “water under the bridge” to a friend who is upset by a mistake he/she has made, we mean “___________.”

A.forget it    B.correct it   C.worry about it  D.avoid it

47.Choose a word to complete the sentence “They gave the press the___________description of what really had happened.”

A.watered-down  B.waters      C.water D.watered

48.Which of the following can be used to describe Jack, who has invested a lot of money in stocks without knowing anything about the stock market?

A.Still waters run deep.

B.Too much water drowned the miller.

C.It is no safe to wading in an unknown water.

D.You can take a horse to water, but you can’t make him drink.

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